7,12-Dimethylbenz(a)anthracene is among the most powerful carcinogenic hydrocarbons known. Probable carcinogenic metabolites of 7,12-dimethylbenz(a)anthracene will be prepared. The isomeric arene oxides of 7,12-dimethylbenz(a)anthracene, the related phenols, trans 1,2-dihydro-1,2-diols and glutathione conjugates will be synthesized. Both C14 and tritium labelled compounds will be prepared. The availability of these compounds will permit determination of the mechanism by which these carcinogenic chemicals trigger the induction of renal tumors. These isomeric arene oxides will be prepared from the corresponding dihydroaromatic compounds. The conversion of dihydroaromatic compounds to arene oxides is well worked out. A new reaction has been discovered which complements existing synthetic methodology and thus makes isomeric dihydroaromatic compounds accessible. Isotopic labelling can easily be accomplished by this new approach. The synthesized metabolites will be tested for their mutagenic activity in the Salmonella histidine revertant system with and without microsomal activation using tester strains TA 98 and TA 100. The most active metabolites will also be tested for their potential to produce malignant transformation utilizing the 10 1/2 CL8 mouse cell line.